Barriers fall into several types of categories: movable median barriers, permanent barriers, concrete median barriers, Quickchange Moveable Barrier (QMB) Systems, and some temporary barriers systems like movable median barrier systems, Polyethylene PVC pylons, delineator median systems, and energy absorbing medians. Barriers systems in general need a minimum of twelve feet to fourteen feet per lane to maintain lane width to adapt the use of prior art barrier systems on a suspension span bridges, truss bridges, or overpasses.
The disadvantages of these types of systems are that permanent median barriers and movable median barriers take up critical and limited lane space on the bridge road surfaces. Wide barriers create smaller lanes, which cause adjoining vehicles to be closer to one another, creating hazardous situations where the small clearance between lanes increase the danger of contact and collision between adjoining vehicles.
Movable median barriers are complex, sometimes difficult to use on existing bridge roads, and time consuming to move when attempting to complete the task of changing lanes.
Delineators cones used today are of a molded polyethylene and/or PVC plastic, in cylindrical form, with colors added to the plastic, and reflector tape wrapped at the top edge. They are designed to warn vehicles of the presence of an opposing lane of traffic. They are usually not used to divert the flow of traffic to one side of a given lane.
Delineator pylons used on suspension span bridges today do not provide a safety margin as far as preventing a head-on collisions. On bridges where opposing traffic flow is on one road surface, this lack of safety margin is a constant problem. A work crew changing the location of pylons by hand while driving across a bridge is also at risk. Handling the pylons by hand is potentially very dangerous to the driver of the vehicle and its occupants, not to mention that such a slow moving vehicle could easily be accidentally misdirected so that it abruptly swerve into the opposing lane of traffic to potentially cause a head-on collision during this process.